San Francisco startup Yard Club helps owners of heavy equipment rent idle machines to one another

Caterpillar Inc. said it had invested in Yard Club Inc., a San Francisco startup that helps owners of heavy equipment rent idle machines to one another, much as Airbnb Inc. helps people find vacant homes or apartments for short stays.

A spokeswoman for Caterpillar, which makes construction and mining equipment, said the company had provided a bridge loan that could be converted to equity in the future. Colin Evran, Yard Club’s 31-year-old chief executive who founded the startup in 2013, declined to provide details of the...